Humidostat



June l2, .M E HENNING HUMIDOSTAT Filed May 9, 1930 2 sheets-sheet 1 SUPPLY M6001 T/a/V M. E. HENNING HUMIDOSTAT 2 Sheets-Sheet 2 Filed May 9, 1930 6 6 6. |||||5- 6 l' N m T .0 M Mz U 5 w W Il@ a. 6 n llzJ a f W 43 A I IH w I 5 W Patented June 12, 1934 UNITED STATES PATENT OFFICE HUlWIDOSTAT Application May 9, 1930, Serial No. 451,042

2 Claims.

The object of my invention is to provide a humidity control switch of simple and durable construction, and which is inexpensive to manufacture.

A further object is to provide a humidity control switch comprising a pair of elements, both susceptible to atmospheric conditions and opposedly mounted relative to each other, with means for alfecting one of the elements by the humidity of the atmosphere, whereby a switch or other` control device may be actuated by the elements depending on different humidity conditions of the atmosphere.

More particularly, it is my object to provide a pair of bellows charged with a volatile liquid or other atmospheric responsive elements opposedly mounted relative to and balancing each other for operating a control device for a humidifier, with a damp wick associated with one of the atmospheric responsive elements, whereby humidity conditions of the surrounding atmosphere will 'affect the balance of the two elements and operate the control device.

Another object is to provide a pair of bellows mounted end to end and a switch operatively connected with them and adapted to be open when the bellows are balanced, a damp wick being associated with one of the bellows, whereby evaporation of the moisture therefrom will lower the temperature surrounding the bellows with which the wick is associated, whereby the switch will be closed for closing the circuit through an electrically operated humidifier.

With these and other objects in view my invention consists in the construction, arrangement and combination of the various parts of my device, whereby the objects contemplated are attained, as hereinafter more fully set forth, pointed out in my claims, and illustrated in the accompanying drawings. Although the invention is susceptible of a variety of embodiments, it is unnecessary to fully describe and illustrate more than one in order to give a full understanding of the invention both from its structural and functional standpoints. Accordingly, I have illustrated a preferred and desirable embodiment of the invention in the accompanying drawings, in which:

Figure 1 is a perspective view o f my humidity control switch illustrating it diagrammatically connected With a humidifier.

Figure 2 is an enlarged sectional view on the line 2 2 of Figure 1.

Figure 3 is a sectional view on the line 3 3 of Figure 2.

Figure 4 is a sectional-view ocn the line 4 4 of Figure 2. l' v Figure 5 is a sectional view on] the'line 5 5 of Figure 3. i f

Figure 6 is a central, sectional'view on the line 6 6 of Figure 3; and

Figure 'I is a sectional View on the line 7 7 of Figure 6. v

On the accompanying drawings I have used the reference numeral lto indicate a base. A supporting bar 12 preferably o f insulation extends outwardly from the base 10. l"A permanent magnet 14 is supported on the bar 12 by a plate 16 and a screw 18. A sheet of insulation 17 is interposed between the magnet 14 and the plate 16. A main contact 20 is supported by a stud 22 on the bar 12. The screw 18 and the stud 22 are electrically connected together by a link 24.

A yoke 26 extends outwardly from the base 10 and pivotally supports a yoke shaped switch arm 28 on pintles 30, The arm 28 is preferably formed of insulating material. An armature arm 32 is secured to the switch arm 28 and is provided with a main contact 34 adapted to coact with the contact 20 when the vswitch is in closed position. A pair of auxiliary contacts 36 are carried by a leaf spring 38 mounted on the armature arm 32 and extend through enlarged openings 40 formed in the armature arm. The auxiliary contacts 36 engage with contacts 42 mounted on the plate i6. In its open circuit position, the arm 32 engages a plate 33 of insulating material.

Lead wires 44 and 46 extend upwardly through' the base l0, one being connected with the screw 18 and the other with a terminal 48. A pig tail connection 50 extends from the terminal 48 to the armature arm 32.

Between the base 10 and the outer end of the yoke 26 is a pair of bellows 52 and 54 mounted end to end. A pin 56 extends between the arms of theA yoke shaped switch arm 28 and sets in a notch 58 formed in a member 60 which connect-s the two bellows 52 and 54 together whereby movement of the member 60 will operate the switch arm 28. Springs 62 and 64 are mounted within the bellows 52 and 54 for normally holding them in a balanced position with the switch open. Each bellows is charged with a volatile liquid, for instance ethyl chloride. At a given temperature this liquid will boil, or become volatile, creating pressure in each bellows, inasmuch as the bellows in each case is the same diameter and the `temperature is approximately the same, thus the pressure created in each bellows will also be approximately the same.

By means of a screw 66 and lock nuts 68, the bellows 52 and 54 may be initially adjusted for properly balancing each other and maintaining the switch open when so balanced, with the pressure balanced in each bellows.

A wick 70, or any suitable fabric, is associated with the bellows 52 and extends into an evaporatable liquid 72, such as water, which is retained in a cup '74. The cup 74 may be removed through an opening 76 in a casing 78 as shown in dotted lines in Figure 4 for replenishing the supply of liquid.

Practical operation In the operation of my device, when the air is humid the switch will remain open. When the air becomes dry, however, it will cause evaporation of the liquid from the damp wick 70 which will lower the temperature surrounding the bellows 52, reducing the pressure therein and thereby causing it to contract and the bellows 54 to expand. This will swing the pin 56 towards the right as viewed in Figures 2 and 6 and will move the switch arm 32 toward closed position, which is illustrated in dotted lines in Figure 2.

In Figure l I have shown the control structure connected with a humidifier motor 80 which operates a fan 82 for blowing air through a damp fabric 84 extending into a liquid container 86. The operation of this device will humidify the air and when it is humidified to such a degree that the air will not evaporate any more moisture from the wick 70, the bellows 54 and 52 will soon balance each other again and open the switch.

There are several typesof electrically operated humidiers, any one of which may be controlled by my device. The adjusting screw 66 can be adjusted for keeping the humidity of a room either high or low, as desired.

Some changes may be made in the construction and arrangement of the parts of my device without departing from the real spirit and purpose of my invention, and it is my intention to cover by my claims, any modified forms of structure or use of mechanical equivalents, which may be reasonably included within their scope.

I claim as my invention:-

1. A humidity responsive device comprising a support, a pair of bellows mounted thereon, said bellows being arranged end to end, a spring within one of said bellows opposing expansion of the other one, a spring in the other oi said bellows opposing expansion of the first mentioned bellows and the other spring, a iiuid container on said support below said bellows, iiuid in said container, and a wick immersed therein and extending over one of said bellows.

2. A humidity responsive device comprising a support, a pair of bellows mounted thereon, said bellows being arranged end to end, a spring enclosed in each bellows whereby said springs oppose each other and each opposes expansion of the bellows enclosing the other one, means for adjusting the outer end of one of said bellows relative to the outer end of the other one, and a damp wick extending around one of said bellows.

MALCOLM E. HENNING. 

